This study is designed to illuminate how enzymes acquire new functions during the course of evolution by mutation and natural selection. The focus is on newly-evolved beta-galactosidases. These new enzymes evolve from a locus called ebg located around 59 minutes on the chromosome map. There are few known loci in this region, and one of the goals of the current year was to obtain a precise genetic map. In addition, we have used ebg mutations to determine the mechanism of a peculiar phenomenon that happens when E. coli cells are grown in lactose-limited chemostats.